On an Internet Protocol (IP) network, one route entry corresponds to one IP address in a routing table on a control plane of a network device. For example, an IP address 192.168.1.1 corresponds to a route entry 192.168.1.0/24. However, a data packet is instructed to be forwarded by a forwarding table (forwarding table) on a forwarding plane (usually a forwarding chip) of the network device. The forwarding table may also be referred to as a forwarding information base (forwarding information base, FIB for short). The forwarding table of the network device is usually generated according to an optimal route in the routing table, or may be generated based on the Address Resolution Protocol (ARP).
The IP network does not ensure high reliability. Anomalies such as data packet loss or error may be caused by a link fault on the network, by a lack of a corresponding forwarding entry to be generated on the network device, by an error in the generated forwarding entry, or by other reasons.